Reproductive disorders part 1 Lecture 7 Flashcards
What reproductive disorders are covered in these lectures?
- Disorders of sexual development
- Infertility
- Menstural disorders
- Disorders of pregnancy
- Gynaecological disorders
- Male reproductive disorders
What is an example of DSD (disorder of sexual development?)
Disorders of gonadal differentiation
Whats a characteristic of all DSD?
Genetically caused.
What are some examples of disorders of gonadal differentiation?
- Klinefelters syndrome (47, XYY) (most common)
- Turners syndrome (45, X)
- Pure gonadal dysgenesis
- True hermaphroditism
Whats the prevalence of klinefelters syndrome?
1 in 600 male live births
What causes klinefelters syndrome?
Meiotic non-disjunction of the x chromosome of either parent (i.e baby ends up XXY)
What happens to the testis in Klinefelters syndrome?
Small firm atrophic testis devoid of sperm cells, impaired leydig cell function and absence of spermatogenesis
How does the extra X chromosome in klinefelters syndrome influence spermatogeneis?
The extra X chromosome does not permit the survival of germ cells in the testis resulting in azoospermia.
What happens to hormone levels in klinefelters syndrome?
Low androgen levels (Leydig cell function impaired)
High levels of FSH and LH and oestrogen’s.
What are some signs and symptoms of klinefelters syndrome?
- Tall 6ft plus
- Small external genitals
- Pear shaped body (feminine)
- Infertile or sterile
- Gynaecomastia (breast development in M.)
- Psychological problems
What causes turners syndrome (45XO)?
Complete or partial X chromosome MONOSOMY in a phenotypic female (i.e they only have on chromosome)
Whats the incidence of turners syndrome?
1 in 2500 live born females (most common chromosome disorder in females)
What does loss of an X chromosome in females turners syndrome lead to?
Loss of an X chromosome, leads to early loss of follicles, lack of ovarian development and usually infertility.
What are the characteristic clinical features of turners syndrome?
- Webbed neck
- Low hairline
- Low set ears
- Widely spaced nipples
- Short stature
- Ovaries, poorly formed or absent
- Incompleted sexual development
What is pure gonadal dysgenesis?
The progressive loss of primordial germ cells in the developing gonads of an embryo. Thus gonads won’t form so baby will appear as female.
Can have 46XX or 46XY.
What causes gondal dysgenesis?
The cause is unknown.
However, Either the germ cells do not form or interact with the gonadal ridge or undergo accelerated atresia so that at the end of childhood only a streak gonad is present, unable to induce pubertal changes.
Thus no T babies appear female.
Whats the incidence of true hermaphroditism?
Very rare
What is true hermaphroditism?
Combination of gonadal tissue is present.
What can form in true hermaphroditism?
Ovotestis- A combination of seminiferous tubules and ovarian follicles
or
Ovary on one side and testis on the other.
How many couples actually seek help for infertility?
1 in 6
When are a couple considered infertile?
A couple is consider infertile after a year of having unprotected sex and failing to become pregnant.
What are some sperm disorders?
- Failed or poor fertilisation
- poor sperm quality
- azoospermia
What is causes failed or poor fertilisation of sperm?
- Sperm factors (poor fertilising capacities)
- Egg factors (thick zone pellucid-smokers)
What causes poor sperm quality?
Oligiospermia (low count)
Teratosoospermia (increased abnormalities)
Asthenozoospermia (decreased motility)
Presence of sperm antibodies
Whats considered normal values for sperm volume, count and motility?
Volume/ml 2-6
count million/mil 20-250
Motility % 50+
What is considered infertile values for sperm volume, count and motility?
Volume/ml <1.5
count million/mil <10
Motility % <35
If a man has sperm problems how can this be remedied?
ICSI: Intracytoplasmic sperm injection
Only one sperm needs to be found in the testis and extracted to perform in vitro fertilisation
Does a low sperm volume correlate with infertility?
Not particularly
Does low sperm count mean infertility?
It doesn’t exclude it (ISCI)
What is sperm motility influenced by?
- Temperature
- Time?